Families clutched mattresses, chairs and other belongings and slogged through waist-high floodwaters Tuesday as Tropical Storm Hanna killed at least 13 people in northern Haiti. The slow-moving storm threatened to hit the southeastern U.S. coast as a hurricane within days.

The 2007 Atlantic hurricane season should be "very active," with nine hurricanes and a good chance that at least one major hurricane will hit the U.S. coast, a top researcher said Tuesday. Forecaster William Gray said he expects 17 named storms in all this year, five of them major hurricanes with sustained winds of 111 mph or greater.

This year's El Nino weather phenomenon, credited with blunting the 2006 hurricane season, is strengthening as winter arrives, which could mean a warmer, drier winter for the northern USA and wetter weather through spring in the south, federal climate officials say.

A leading tropical forecast team predicted Tuesday that next year's season will be "very active," with a well-above-average number of major storms. In its first forecast for 2006, the Tropical Meteorology Project at Colorado State University expects 17 named tropical storms in the June-November season.